Automated Material Handling Systems (AMHS) have been widely used in semiconductor fabrication facilities to automatically handle and transport groups or lots of wafers between various processing machines used in chip manufacturing. A fabrication facility includes one or more floors having a plurality of process bays including processing tools and wafer staging equipment which are interconnected by the AMHS.
A bay includes a wafer stocker, which includes multiple bins for temporarily holding and staging wafer carriers during the fabrication process. The wafer carriers include front opening unified pods (FOUPs) which hold, inter alia, larger 300 mm (12 inch) wafers. A stocker generally includes a single mast robotic lift or crane for lifting, inserting, and retrieving wafer carriers from the bins. The stocker generally holds multiple FOUPs in preparation for transporting a FOUP to the loadport of a processing tool.
A semiconductor fabrication facility includes numerous types of automated and manual vehicles for moving and transporting wafer carriers throughout the fabrication facility during the manufacturing process. A vehicle handling system automatically moves the vehicles that carry and transport wafer carriers, such as FOUPs from a processing tool or a stocker to the loadport of another tool or other apparatus.